Sharma Veerendra K, Ghosh Sajal K, García Sakai Victoria, Mukhopadhyay R
Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, India.
Homi Bhabha National Institute, Mumbai, India.
Front Chem. 2020 Nov 19;8:577508. doi: 10.3389/fchem.2020.577508. eCollection 2020.
Ionic liquids (ILs) are an important class of emerging compounds, owing to their widespread industrial applications in high-performance lubricants for food and cellulose processing, despite their toxicity to living organisms. It is believed that this toxicity is related to their actions on the cellular membrane. Hence, it is vital to understand the interaction of ILs with cell membranes. Here, we report on the effects of an imidazolium-based IL, 1-decyl-3-methylimidazolium tetrafluoroborate (DMIM[BF4]), on the microscopic dynamics of a membrane formed by liver extract lipid, using quasielastic neutron scattering (QENS). The presence of significant quasielastic broadening indicates that stochastic molecular motions of the lipids are active in the system. Two distinct molecular motions, (i) lateral motion of the lipid within the membrane leaflet and (ii) localized internal motions of the lipid, are found to contribute to the QENS broadening. While the lateral motion could be described assuming continuous diffusion, the internal motion is explained on the basis of localized translational diffusion. Incorporation of the IL into the liver lipid membrane is found to enhance the membrane dynamics by accelerating both lateral and internal motions of the lipids. This indicates that the IL induces disorder in the membrane and enhances the fluidity of lipids. This could be explained on the basis of its location in the lipid membrane. Results are compared with various other additives and we provide an indication of a possible correlation between the effects of guest molecules on the dynamics of the membrane and its location within the membrane.
离子液体（ILs）是一类重要的新兴化合物，尽管它们对生物体有毒性，但由于其在食品和纤维素加工用高性能润滑剂等广泛的工业应用中。据信这种毒性与它们对细胞膜的作用有关。因此，了解离子液体与细胞膜的相互作用至关重要。在此，我们使用准弹性中子散射（QENS）报告了一种基于咪唑鎓的离子液体1-癸基-3-甲基咪唑四氟硼酸盐（DMIM[BF4]）对肝提取物脂质形成的膜的微观动力学的影响。显著的准弹性展宽的存在表明脂质的随机分子运动在该系统中是活跃的。发现两种不同的分子运动，（i）膜小叶内脂质的横向运动和（ii）脂质的局部内部运动，对QENS展宽有贡献。虽然横向运动可以假设为连续扩散来描述，但内部运动是基于局部平移扩散来解释的。发现将离子液体掺入肝脂质膜中通过加速脂质的横向和内部运动来增强膜动力学。这表明离子液体在膜中诱导无序并增强脂质的流动性。这可以根据其在脂质膜中的位置来解释。将结果与各种其他添加剂进行了比较，并且我们给出了客体分子对膜动力学的影响与其在膜内的位置之间可能存在的相关性的指示。
